<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    button.active{
      background-color: red;
    }
    .content{
      width: 200px;
      height: 200px;
      border: 1px solid #333;
    }
  </style>
</head>
<body>
  <div id="app">
    <button 
      v-for="(nav,index) in arr" 
      :class="{active: num === index}" 
      @click="tab(index)"
      :key="nav.title">
      {{ nav.title }}
    </button>
    
    <div v-for="(content,index) in arr" :key="index" v-show="num===index" class="content">
      {{ content.content }}
    </div>
    
  </div>
  <script src="./vue.js"></script>
  <script>
    const vm = new Vue({
      el:"#app",
      data: {
        arr: [
          {
            title:"标题1",
            content:'内容1'
          },
          {
            title:"标题2",
            content:'内容2'
          },
          {
            title:"标题3",
            content:'内容3'
          },
          {
            title:"标题4",
            content:'内容4'
          }
        ],
        num: 0
      },
      methods: {
        tab(n){
          this.num = n;
        }
      }
    })
  </script>
</body>
</html>